1. Field of the Invention
This invention relates generally to a device for manipulating information, and relates more particularly to a device for manipulating information in an audio decoder.
2. Description of the Background Art
Implementing an efficient and effective method for manipulating digital information is a significant consideration of system designers and manufacturers. However, the techniques available to manipulate the digital information often requires expensive modification of existing hardware or the development of new hardware.
Digital information is now in widespread use in consumer products such as compact disc (CD) players, digital video disc (DVD) players, digital video broadcast (DVB), and other systems. This widespread use of digitized audio and video information in the consumer market has led to a demand for more information to be incorporated in a single, convenient form. For example, entire movies may need to be included on a single CD. This demand led, in part, to the development of digital video discs (DVDs).
A single DVD may hold up to twenty-five times more information than a conventional CD. Thus, a single DVD is capable of holding both the video and audio portions of an entire two-hour movie. In addition, a DVD has the capacity to hold variety of other information such as widescreen picture information, six-channel surround sound, multilingual audio tracks, subtitles, and multiple camera angles. These features are not available on a CD because of capacity limitations.
DVD was developed with a standardized file format for the audio portion of the individual data. The standardized file format bundles data into packets of information. Each packet contains a header portion and the audio data portion. The header portion typically contains parameters that the audio system uses to process and playback the audio data. For example, the parameters may contain information about the audio data format, the playback speed, whether the audio data has been downsampled, or the type of data compression used.
A typical DVD system transfers the audio and video data in a continuous stream in which each packet is transferred in sequence. The DVD system transfers each packet beginning at a specific time interval. Until now there has been no convenient method to analyze the parameters within each packet before audio playback. This, in turn, has meant that developers have been unable to modify existing playback systems or to develop new, low-cost systems that advantageously use the information contained in the parameters. In addition, developers have been unable to incorporate user-entered host parameters into the audio data to manipulate the audio playback systems directly from the data. The foregoing problems thus present significant obstacles for effectively implementing an efficient method to manipulate digital information.